Rome -LRB- CNN -RRB- -- Amanda Knox 's ex-boyfriend and murder trial co-defendant revealed in a new book that he sometimes questioned her innocence because of her `` bizarre behavior '' the day a British student was found dead in their apartment .

Raffaele Sollecito 's memoir , `` Honor Bound : My Journey to Hell and Back with Amanda Knox , '' is the first book written by anyone directly involved in the Meredith Kercher murder trial in Perugia , Italy .

Kercher , a 21-year-old British student , was found stabbed to death in the Italian apartment she shared with Knox , now 25 , of Seattle .

Sollecito and Knox were convicted of Kercher 's murder in 2009 but set free on appeal in 2011 . They face a final high-court decision in March .

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Rudy Guede of Ivory Coast was convicted separately in 2008 . His conviction was upheld on appeal in 2009 .

Sollecito 's book draws heavily on diaries he kept and letters he wrote to friends , family and his hometown newspaper during his years in prison , the preface says .

He chronicles the day of the murder , admitting that he and Knox smoked marijuana that afternoon , which he says he regretted because it clouded his memory of what happened . While maintaining his innocence , he says he does not clearly remember even if Knox spent the night with him .

He and Knox made mistakes the morning of the discovery , including trusting police investigators , he writes .

Sollecito writes that at times , he was uncomfortable with Knox 's `` bizarre behavior , '' which he says prosecutors used against both of them .

`` Of all the things that Amanda did that day , nothing attracted more criticism than her failure to raise the alarm as soon as she saw so many things out of place , '' he writes . `` It was n't just the police who attacked her . Many Italians , including most of my family , could not fathom how she could go ahead with her shower after finding blood on the tap , much less put her wet feet on the bath mat , which was also stained , and drag it across the floor . ''

Neither he nor Knox had solid alibis for the night of Kercher 's murder , Sollecito writes .

`` We had no real alibi for the night of November 1 except each other , and we did not have lawyers to protect us , and we seemed to have a propensity for saying things without thinking them through , '' he says .

Sollecito describes his doubt about Knox 's innocence at times , referring to the night the two were arrested .

`` When I first found out about what Amanda had signed her name to , I was furious , '' he writes . `` Okay , she was under a lot of pressure , as I had been , but how could she just invent stuff out of nowhere ? ''

He gives an account of his life inside several Italian prisons , where he befriended rapists and murderers , played with cockroaches and scrubbed the cells of dirt and mold .

While sharing his family 's personal stories and sagas during the lengthy trial , the book gives very little attention to the evidence presented in court .

The revelations include how he distrusted the lawyers his father hired for him . They were intent on getting Sollecito to abandon Knox and accuse her of the murder , he wrote .

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At one time after the first conviction , Sollecito 's father sought the help of a private lawyer not connected to the case , who spoke to Perugia prosecutor Giuliano Mignini about striking a plea deal to cut Sollecito 's sentence in exchange for evidence against Knox .

Sollecito 's lead attorney , Giulia Bongiorno , a prominent parliamentarian , almost walked off the case because of the backroom deal .

Mignini declined to comment about the book or the case until the high court appeal is completed .

Sollecito 's book is especially hard on Mignini , whom he accuses of concocting a `` conspiracy-laden plotline from Umberto Eco '' instead of a normal investigation .

He laments the star treatment Knox received , saying the prosecution focused squarely on his co-defendant . He wrote that he believed he was arrested as a way to get to Knox .

`` I do n't think the prosecution or police ever seriously thought of me as a murderer , '' he wrote . `` They had one overriding reason to arrest me , throw me into solitary confinement , and threaten me with life imprisonment , and that was to pressure me into rolling over and testifying against Amanda . ''

Sollecito condemns his treatment by Perugia police who , he says , would not give him food or access to a lawyer during the questioning , even though it was clear to him that they were treating him as a suspect and not just a person informed of the facts of the case .

Sollecito gave several spontaneous declarations during both the original and appellate trials , but he never took the stand in his own defense .

The book offers many details from behind the scenes during the four years between when Kercher was killed and when the two were released , but it does not answer all the questions about what happened that night .

Sollecito wrote that he believed that Guede acted alone in killing Kercher .

In the epilogue , Sollecito recounts how he went to visit Knox in Seattle last fall , but how he was nervous to see her . `` I was n't at all sure it was a good idea and I continued to waver back and forth even after I booked my ticket . We had been through so much ; perhaps we owed it to each other to live our lives and leave each other in peace . ''

Guede is writing a book but does not have a publisher , according to his lawyers . Knox 's book is due to be released in the spring .

Knox signs book deal with Harper Collins

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Raffaele Sollecito wrote `` Honor Bound : My Journey to Hell and Back with Amanda Knox ''

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Sollecito and Knox were convicted of murder but later freed on appeal

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Meredith Kercher was found stabbed to death in the apartment shared with Knox